Press-stud

ABSTRACT

A press-stud comprises a male component which is selectively insertable by snap-fitting into a female component. The female component ( 10, 10′, 40 ) comprises a main body ( 11, 11′, 41 ) in which is housed a resilient annular member ( 13, 43 ), held within the main body by a cap ( 12, 12′, 42 ) fixed to the peripheral end of an annular appendage ( 23, 23′, 48 ) of the main body ( 11, 11′, 41 ). Different caps can be attached by modifying the configuration of the annular appendage ( 23, 23′, 48 ) only.

The present invention relates to an improved press-stud.

Press-studs, also called snap-studs because of the typical effect noticeable during buttoning and unbuttoning, are composed of a male component which is snap-fitted into a female component, in which it is retained by a wire bent into an omega shape, which exhibits resilient behaviour. The omega-shaped wire locks a head of the male component within a cavity of the female component until sufficient force is exerted to separate the two components by overcoming the resilient force of the omega-shaped wire, which is thus widened to allow the head of the female component to pass through.

Known press-studs of the aforementioned type have a number of drawbacks in terms of both function and appearance. The omega-shaped wire is subject to oxidation and hardening, causing a change over time in its resilient behaviour and therefore in the retention characteristics of the press-stud. The oxidation of the wire is also displeasing, because it may damage and stain the items to which the press-stud is fixed, such as garments, curtains, bags, or the like. Moreover, the omega bend of the wire creates an asymmetry in the resilient force exerted on the male component when it is inserted into the female component during buttoning. The practical outcome is that the snap-fitting stiffness of the same press-stud varies according to its orientation. Consequently, for example, in a row of studs attached to a garment, the snap-fitting stiffness will be different for each press-stud in the row, according to its orientation. Moreover, it is practically impossible to orientate press-studs of the known type in the same way, because they are normally small in size, and also because this would considerably complicate the production process.

In terms of appearance, known press-studs of the aforementioned type are subject to a number of constraints in relation to their construction, which severely limit the possibilities of modifying or customizing their appearance. In particular, the omega-shaped wire has to be contained in a housing having a certain thickness, which must be provided with suitable lateral slots in which the ends of the omega-shaped wire are engaged, to ensure the correct operation of the press-stud. The appearance of the female element is therefore highly dependent on, and limited by, the functional characteristics of the snap-fitting and retention device of the press-stud.

Numerous attempts have been made over a period of time to overcome the aforementioned drawbacks. With respect to appearance, for example, the present applicant has devised a press-stud with a wire in which a conventional snap-stud is covered with a frustoconical shaped cap having rounded edges, this stud being registered as Community model no. 001623422-0002. The addition of this shaped cap provides a pleasing result in terms of appearance, but contributes to an increase in the thickness, and to some extent the weight, of the snap-stud. The use of this solution is therefore limited to applications in which the weight or overall dimensions of the press-stud is not a stringent or binding requirement.

In relation to the technical and functional aspects, press-studs have also been proposed in which the resilient retaining action is provided by a ring of synthetic material. Press-studs of this type are described, for example, in the documents WO 1997/15207 and WO 2009/101541 filed by the present applicant. The synthetic rings described in these documents are hexagonal in plan view, and are supported within the female element substantially by bearing on the vertices of the hexagon, where the cross section of the synthetic ring is also enlarged. The portions of the ring between adjacent nodes are resiliently deformable and provide resilient retention of the head of the male element in the buttoned configuration of the press-stud. To achieve good retention functionality which will remain constant over time, the thickness of the synthetic ring described in the aforementioned documents cannot be reduced below a certain level, which makes it difficult to produce small press-studs having good characteristics of retention and snap-fitting stiffness. The shape of the resilient ring, which is necessary to ensure good snap-fitting functionality and retention in the press-stud, makes it difficult to use caps of different shapes, especially if small press-studs are required.

Another type of resilient member for providing retention in press-studs is described in the document EP 2 441 340 filed by the present application. It is formed by a flat ring, the inner edge of which is interrupted by cuts to form flexible tabs which bend substantially in the axial direction of introduction and extraction of the male component to allow the passage of the head. The provision of this resilient member enables very thin, flat press-studs to be produced, but it requires precision in the design and in the assembly of the female component in order to achieve a precise snap-fitting stiffness which is sufficient and uniform from one press-stud to another.

The object of the present invention is, in the first place, to overcome the drawbacks of a press-stud with an omega-shaped wire as described above. Another object of the invention is to provide a press-stud having a snap-fitting stiffness which is sufficiently precise, long-lasting and uniform from one press-stud to another. A further object of the invention is to produce a press-stud of relatively small size which can be modified easily to obtain configurations of various kinds, thereby promoting the development of varied, aesthetically pleasing shapes, without requiring the modification, or at least the substantial modification, of the functional elements of the press-stud. A further object of the invention is to provide a press-stud which is simple, reliable and economical. In general terms, therefore, an aim of the present invention is to provide a snap-stud having a combination of elements adapted to provide a useful and harmonious combination of the best characteristics found in known snap-studs, with particular reference to the effectiveness and durability of the retention and the simultaneous possibility of providing a small, lightweight stud which can be configured in various ways in respect of shape and decoration.

In order to achieve the aforementioned objects, the present invention proposes a press-stud having the characteristics described in the appended claims.

In particular, the press-stud according to the present invention comprises a male component which is selectively insertable by snap-fitting into a female component, the female component comprising a main body in which is housed a resilient annular member held within the main body by a cap fixed to the peripheral end of an annular appendage of the main body, different caps being attachable by modifying the configuration of the annular appendage only.

According to an advantageous feature of the present invention, modifying the configuration of the annular appendage only comprises the inclination and/or curving of the appendage with respect to a plane orthogonal to the direction of buttoning. These modifications can easily be made without the need for radical alterations in the production machinery and installations, making it possible to achieve high flexibility at low cost in the manufacture of press-studs having different configurations but identical performance.

According to another advantageous feature of the present invention, the cap comprises an edge which is tightly turned around an end of the annular appendage, thus enabling the cap to be attached rapidly and securely.

According to a further advantageous feature of the present invention, the annular appendage also acts as a support for at least part of the cap, providing a backing for it and enabling even relatively large or thin caps to be used without any risk of their deformation in use.

According to a further advantageous feature of the present invention, the annular appendage also acts as a support for an outer flange of the resilient annular member. This configuration is particularly advantageous in that it enables the resilient annular member to be fastened to the main body of the female component before the cap is attached, thus facilitating the process of manufacturing the press-stud according to the invention.

According to yet another advantageous feature of the present invention, the resilient annular member comprises a relatively massive outer annular portion, from which radial lips, having a cross section relatively thinner than that of the outer annular portion, extend inwards. Thus the characteristics of the snap-fitting and locking action of the resilient annular member on the male component of the snap-stud are not affected by the way in which the male component is engaged or supported within the female component.

According to another advantageous feature of the present invention, the radial lips have a hook-like configuration, with a tip substantially aligned with the upper face of the outer annular portion of the resilient annular member, and separated therefrom by a circumferential groove. This resilient annular member exhibits excellent locking performance which is reliable and constant over time.

Additionally, the upper face of the outer annular portion of the resilient annular member may be configured so as to slope gently towards the outside, where it is rounded off. This configuration makes it possible to provide press-studs having caps which may be flat, domed, or inclined, without the need to modify the resilient annular member and without any effect on its snap-fitting and locking performance.

According to a further advantageous feature of the present invention, the radial lips of the resilient annular member are separated from one another by deep longitudinal indentations which also extend into part of the outer annular portion, in order to optimize the snap-fitting and locking performance of the resilient annular member.

A press-stud according to the invention has numerous advantages. For example, it is possible to provide press-studs in which the female component has a pleasing appearance which can be modified without excessive effort in order to meet the requirements of customization, the prominence and popularity of which is increasing, in the fashion industry for example. Such customization is possible at low cost while still yielding excellent results in terms of quality.

Another advantage of the press-stud of the present invention is the fact that the male component does not require any particular modification compared with the component used in an ordinary press-stud with an omega-shaped wire.

Further characteristics and advantages of the invention will become apparent from the following detailed description of preferred, but non-limiting, embodiments, with reference to the attached figures, also provided purely by way of non-limiting example, in which:

FIG. 1 is a cross section through a female component according to a first embodiment of the present invention;

FIG. 2 is a cross section through a female component according to a second embodiment of the present invention; and

FIG. 3 is a cross section through a female component according to a third embodiment of the present invention.

With reference to FIG. 1, a female component 10 of a press-stud, the male component of which is not shown in the figure, comprises a main body 11 on which is mounted a cap 12, which holds a resilient ring 13 in the female component 10. The main body 11 is preferably symmetrical about an axis Z-Z which is substantially parallel to the direction of insertion and detachment of the male component in the operations of buttoning and unbuttoning the press-stud. The main body 11 comprises a cup-shaped portion 14 designed to receive the head of the male component in the buttoned configuration of the press-stud. An opening 15 is made in the bottom 16 of the cup-shaped portion 14 for fastening the female component 10 to a substrate in a known way. In the part opposite the bottom 16, the edge 17 of the cup-shaped body 14 is widened transversely to the axis Z-Z so as to form an annular base 18 for supporting the resilient ring 13, particularly as regards a substantially flat lower annular face 19 of the latter. The edge 20 of the annular base 18 is bent and extends in the form of a cylindrical lateral containing wall 21 for the resilient ring 13, particularly as regards a cylindrical outer face 22 of the latter. An annular appendage 23 extends outwards from the cylindrical lateral wall 21, and, in the example of FIG. 1, lies on a plane which is substantially transverse with respect to the axis Z-Z. The peripheral edge 24 of the annular appendage 23 is shaped in the form of a conical frustum and terminates in a short flat rim 25.

The cap 12 comprises a central opening 26, normally circular, delimited by a flat annular wall 27 which bears on the annular appendage 23 of the main body 11 and which is turned over externally to form an outer cylindrical wall 28 whose edge 29 is tightly turned around the short rim 25 of the peripheral edge 24 of the main body 11. An inner edge 27 a of the flat annular wall 27 of the cap 12 holds the resilient ring 13 within the female component 10, and particularly within the housing 31 formed by the annular base 18 and by the cylindrical lateral containing wall 21 of the main body 11. The flat annular wall of the cap 12 is designed in such a way that its inner edge 27 a covers a greater part of the resilient ring 13, while leaving free the radial lips 30 which extend radially towards the central area of the female component for a short distance beyond the edge of the central opening 26.

In greater detail, the resilient ring 13 comprises an outer annular portion 32 which has the function of providing a firm support for the resilient ring 13 in the housing 31 of the female component 10. The outer annular portion 32 has a relatively massive cross section by comparison with the radial lips 30, which project from the outer annular portion 32 of the resilient ring 13 in a configuration approximating a hook shape, the tip 33 of which is substantially aligned with the upper face 35 of the outer annular portion 32, being separated from the latter by a circumferential groove 34. The upper face 35 slopes gently towards the outside, where it is rounded off. The radial lips 30 are separated from one another by deep longitudinal indentations 36 which also extend into part of the outer annular portion 32.

In the example of FIG. 1, the number of radial lips 30 is three, so that the snap-fitting stiffness during the insertion or extraction of the male component into or from the female component is always substantially uniform, independently of the mutual orientation of the two components, thereby overcoming one of the drawbacks of the known press-studs with omega-shaped wires. Clearly, it is possible to provide a snap-stud according to the present invention in which the resilient element has a different number of radial lips, which may also differ in their shape, cross section and dimensions.

The configuration of the resilient ring 13 described above with reference to its preferred embodiment shown in FIG. 1 offers a number of advantages. The clear geometrical and functional separation between the outer annular portion 32, which acts as a stable support for the resilient ring 13 within the female component 11, and the radial lips 30, which are primarily responsible for the snap-fitting stiffness and the retention of the male component in the female component, yields significantly advantageous results in terms of reliability, repeatability and uniformity of the retention of the press-stud. In some cases, the particular configuration of the radial lips 30 may also allow the use of the same male components as those of known press-studs which use omega-shaped wires, thus yielding savings in terms of production and storage. The outer annular portion 32 may also act as a support for the inner edge 27 a of the cap 12, without any significant effect on the snap-fitting stiffness and retention characteristics provided by the radial lips 30. Thus it is possible to reduce the degree of precision required during the operations of assembling the cap 12 on to the main body 11.

In the light of the configuration described above and illustrated in FIG. 1, it is clear that variations in appearance, which may be significantly different from one another, can be obtained with a minimum of effort in the press-stud according to the present invention. For example, it is possible to vary the curvature and/or the inclination of the annular appendage 23 only, and correspondingly those of the cap 12, to produce the flat stud shown in FIG. 1, or a domed or frustoconical stud as depicted in detail in FIG. 2.

FIG. 2 shows a press-stud according to the present invention, illustrating the advantages of providing a variant appearance of the female component by making a very few simple modifications to the version shown in FIG. 1. For this purpose, identical reference numbers are used in both figures to denote identical parts, the description of which will not be repeated.

By contrast with the female component 10 of FIG. 1, which has a substantially flat appearance, FIG. 2 shows a female component 10′ which has a generally frustoconical appearance. This is achieved by the shaping of the main body 11′, which differs from the corresponding main body 11 of FIG. 1 solely in the frustoconical shape of the annular appendage 23′ which extends outwards from the cylindrical lateral containing wall 21 of the resilient ring 13. Advantageously, the frustoconical shape of the annular appendage 23′ is produced simply by bending, starting from a main body with a flat annular appendage, as shown in FIG. 1. Unlike the annular appendage 23 of FIG. 1, which lies on a plane which is substantially transverse to the axis Z-Z, the annular appendage 23′ of FIG. 2 is therefore inclined relative to the same axis Z-Z. This simple modification makes it possible to attach to the main body 11′ a cap 12′ having a frustoconical annular wall 27′ which bears on the annular appendage 23′ of the main body 11′, with a result which is functionally similar to that of the female component 10 of FIG. 1, but is very different in terms of appearance.

FIG. 3 shows another embodiment of the press-stud according to the present invention. A female component 40 comprises a main body 41 on which is mounted a cap 42, which holds a resilient ring 43 in the female component 40. The main body 41 is preferably symmetrical about the axis Z-Z which is substantially parallel to the direction of insertion and detachment of the male component in the operations of buttoning and unbuttoning the press-stud. The main body 41 comprises a cup-shaped portion 44 for receiving the head of the male component in the buttoned configuration of the press-stud. An opening 45 is made in the bottom 46 of the cup-shaped portion 44 for fastening the female component 40 to a substrate in a known way. At the end opposite the bottom 46, the edge 47 of the cup-shaped body 44 is widened and extends outwards while curving so as to form a slightly convex annular appendage 48, on which an outer flange 49 of the resilient ring 43 bears, the peripheral edge 50 of this flange being clamped by an end return 51 of the annular appendage 48 of the main body 41.

The cap 42 comprises a central opening 56, normally circular, delimited by a frustoconical annular wall 57, whose inner edge 57 a bears on the resilient ring 43, while its outer edge is bent over to form an outer cylindrical wall 58 whose edge 59 is tightly turned around the end return 51 of the annular appendage 48 of the main body 41. In this embodiment also, as in those shown in FIGS. 1 and 2, the annular wall 57 of the cap 12 is designed in such a way that its inner edge 57 a covers a greater part of the resilient ring 43, while leaving free the radial lips 30 which extend radially towards the central area of the female component for a short distance beyond the edge of the central opening 56. Except for the outer flange 49, the resilient ring 43 is practically identical to the resilient ring 13 of the embodiments shown in FIGS. 1 and 2, and the same description, with the same reference numbers, is applicable to it, while it also has the same advantages.

Again in the case of the female component 40 of FIG. 3, variations in appearance, which may be significantly different from one another, can be obtained with a minimum of effort. For example, it is possible to vary the curvature and/or the inclination of the single annular appendage 48, and correspondingly those of the cap 42, to produce flat, domed or frustoconical stud having a different inclination from that shown in FIG. 3. The outer flange 49 of the resilient ring 43 is also resilient, and can therefore be adapted to the different shape of the annular appendage 48 without the need to provide different resilient rings when the configuration of the female component 40 is changed.

The press-stud according to the present invention, and more specifically its female component whose characteristics are described above, is naturally subject to numerous possible variations which do not alter its features or depart from the scope of protection of the present invention. For example, the cap could have a lateral edge which is indented instead of cylindrical, our could have its upper walls decorated, etched, indented, painted, modelled or otherwise decorated in various ways.

The resilient ring is made of synthetic material, so that it can be formed in a simple way, for example by stamping or press-moulding, and does not have the drawbacks of oxidation and hardening of the wires found in known press-studs. The shape of the radial lips of the resilient ring provides a good degree of retention and correct snap-fitting stiffness even with a male component of the type conventionally used in known press-studs with wires, which usually has a spherical head with a relatively thin neck. 

1. A press-stud comprising a male component which is selectively insertable by snap-fitting into a female component, the female component comprising a main body in which is housed a resilient annular member, held within the main body by a cap fixed to the peripheral end of an annular appendage of the main body, different caps being attachable by modifying the configuration of the annular appendage only.
 2. A press-stud according to claim 1, wherein modifying the configuration of the annular appendage only comprises the inclination and/or curving of the appendage with respect to a plane orthogonal to the direction of buttoning.
 3. A press-stud according to claim 1, wherein the cap comprises an edge tightly turned around an end of the annular appendage.
 4. A press-stud according to claim 1, wherein the annular appendage also acts as a support for at least part of the cap.
 5. A press-stud according to claim 1, wherein the annular appendage also acts as a support for an outer flange of the resilient annular member.
 6. A press-stud according to claim 1, wherein the resilient annular member comprises a relatively massive outer annular portion, from which radial lips, having a cross section relatively thinner than that of the outer annular portion, extend inwards.
 7. A press-stud according to claim 6, wherein the radial lips have a hook-like configuration, with a tip substantially aligned with the upper face of the outer annular portion and separated therefrom by a circumferential groove.
 8. A press-stud according to claim 6, wherein the radial lips are separated from one another by deep longitudinal indentations which also extend into part of the outer annular portion.
 9. A press-stud as described and illustrated and for the specified purposes. 